Electromagnetic linear actuators of an inchworm type are known and one common solution is achieved by directly moving an actuator armature in small steps using piezoelectric, electromagnetic, or magnetostrictive armature translators. Such translators can move the armature in nanometer increments, and can exert very large forces, because they rely on the stiffness of an expanding or contracting material. For example, electromagnetic linear actuators of an inchworm type are disclosed in U.S. Pat. No. 5,027,027 (Orbach et al.), U.S. Pat. No. 3,902,085 (Bizzigotti) and U.S. Pat. No. 3,902,084 (May, Jr.). The performance efficiency of the actuators disclosed in those prior art documents is limited due to the limitation of the structures thereof.
Improvements to the field of electromagnetic actuators are available, however.